The inventive subject matter relates to power distribution apparatus and methods of operating the same and, more particularly, to power distribution test apparatus and methods.
Ground and test devices are commonly used to create an electrically safe environment when working on enclosed medium voltage electrical switchgear. These devices typically have a chassis designed to be installed in a draw-out switchgear compartment and include contacts configured to engage phase and/or load conductor buses in the switchgear compartment when the device is installed. The ground and test device may be configured to ground the line and/or load conductors, and may include test ports or other features to facilitate testing.
A standard for ground and test devices is IEEE C37.20.6 “IEEE Standard for 4.76 kV to 38 kV Rated Ground and Test Devices Used in Enclosures.” The standard identifies four types of ground and test devices: (1) simple manual; (2) complex manual; (3) simple electrical; and (4) complex electrical. A simple manual device has upper and/or lower terminals with provision for connecting phase conductors to ground. A complex device has upper and/or lower terminals and has a manually operated switch configured to connect the upper or lower terminals to a set of test terminals which, in turn, may be connected to ground. A simple electrical device has a set of upper terminals or a set of lower terminals and an electrically operated switch that is configured to connect the upper or lower terminals to ground even if the system is energized. A complex electrical system has a manually operated switch that is configured to connect upper and/or lower terminals to a power-operated grounding switch, and may be used to apply a ground even if the system is energized.